I think I've probably said my part FL, and I chose Mysterious Powers in the poll.
But iffin I had my druthers I see advantages to all your choices.
But I'd add one more thing I think. Good for the Player. That is there is something about it that matches, or corresponds to, or is sympathetic with/towards the nature and personality of the player, and to the character he/she plays.
For instance a lot of magical items had backgrounds and histories that hinted at the characters and natures of their previous owners. I always liked the idea of the Holy Avenger cause it was the Paladin's Right arm, and the Staff of the Magi cause it was an extension of the mind of the Wizard.
But sometimes a magical item just fit a person. Like a glove. Fit their character, their nature, their personality, their manner of operating. View of the world.
I'd prepare magical items just for certain players.
Because they were extensions of the players.
That's something the game (and the designers) can't really prepare ahead of time at the strategic level but the DM can create at the tactical level.
Magical items that are in sympathy, that's about the best term I can put forth, in sympathy with your players. It gives the magical item its own personality, and it further enhances the personality of the character.
Those kinda magical items are just that much more magical.
That's the kinda thing that is magical not by virtue of the fact that it can do this or that, but because it becomes a part of the character. Another aspect of his nature. Part of his soul.